+By default, changes to a read-write WIM are made in-place by appending to the
+WIM. This is ideal for big WIM files, since the entire file doesn't have to be
+rebuilt to make a small change. But, if you are making many changes to a
+read-write mounted WIM, especially deleting large files, it is suggested to
+provide the \fB--rebuild\fR option to \fBimagex unmount\fR to force the WIM to
+be rebuilt, or else run \fBimagex optimize\fR on the WIM afterwards.
+